A prior art network is of common general knowledge. A first node transmits a request message to a second node and receives in return an allocation message from the second node. These messages are related to one and the same signalling procedure.
The known network is disadvantageous, inter alia, due to its nodes sometimes being capable to handle different signalling procedures. In that case, for each one of the signalling procedures, a request message and an allocation message need to be exchanged. This is relatively inefficient (two separate round trips).